Double-Cyclized Dipeptides for Hierarchical Self-Assembly Into Crystalline Macroscopic Superhelices

Cyclic peptides have attracted significant attentiondue to their persistent structures and particular biological effects, which are also key building blocks for creating functional chiral materials. Here, we report a double-cyclized dipeptide structure-a macrocycle embedded with a cyclic dipeptide-and its use in constructing superhelical structures. By further cyclizing modified cyclic diphenylalanine, a macrocyclic arene embedded with a cyclodipeptide was synthesized. Its unique, rigid structure allows to give hierarchical helical structures by bottom-up assembly process in solution. These superhelical structures are macroscopic, reaching lengths of at centimeter scale. This demonstrates a bottom-up, multiscale transfer of chirality from the molecular to the macroscopic scale. Moreover, assembly patterns can be precisely controlled by adjusting kinetic conditions such as temperature, concentration, enantiomeric ratio, and solvent, allowing for both rigid and flexible arrangement modalities. The presence of the macrocycle in these superhelices enables the encapsulation of cationic dyes, leading to both ground-state and excited-state chirality transfer. This provides a valuable template for designing macroscopic chiroptical materials.